Apparatus for threading closures onto bottles and similar containers

ABSTRACT

A rotary shaft and a rotary closure-engaging device which entrainingly engages a closure to be threaded onto a container, are connected by a coupling arrangement having one coupling member connected with the shaft and another coupling member connected with the closure-engaging device. One of these members is provided with a plurality of torque-transmitting elements which engage a circumferential surface of the other member in torque-transmitting relationship but are so yieldably mounted that when a predetermined torque limit is exceeded, a small fraction of the torque-transmitting elements becomes disengaged from the circumferential surface.

United States Patent Keller et al.

[4 Oct. 21, 1975 [54] APPARATUS FOR THREADING CLOSURES 2,909,047 10/1959Miiller et al. 192/56 R X O O BOTTLES AND SIMILAR 3,002,206 10/1961Johnson 192/56 R X 3,106,274 10/1963 Madsen 64/29 X CONTMNERS 3,185,2755/1965 Orwin 192/56 R [75] Inventors: Dieter Keller, Neu-Ulm; Rudolf3,319,723 5/1967 Kramer.. 64/29 X Kuhn, Gunzburg; Dotzauer, 3,754,4128/1973 Briggs 192/56 R X Strass, all of Germany [73] Assignee: FurstlichHohenzollernsche 'Tf i g g Huttenverwaltung Laucherthal, Asslsmm s gLaucherthal, Germany ttorney, gent, 0r trm- 10 ac tr1 er PP 432,627 Arotary shaft and a rotary closure-engaging device which entraininglyengages a closure to be threaded 30 Foreign Appncation p i it Data ontoa cctmiainer, are connelcted by a) coupling tag rangemen avmg one coupmg mem er connec e Jan. 18,1973 Austria 402/73 with the Shaft andanother oupling member C011- [52] U S Cl 53/331 64/29, 19256 R nectedwith the closure-engaging device. One of these [51] F1615 Z 1 43/20members is provided with a plurality of torque- [58] Fieid 53/317 h 5314 77 transmitting elements which engage a circumferential 9 334 192/5- 2 surface of the other member in torque-transmitting relationshipbut are so yieldably mounted that when a predetermined torque limit isexceeded, a small frac- [56] References cued tion of thetorque-transmitting elements becomes dis- UNITED STATES PATENTS engagedfrom the circumferential surface. 2,705,101 3/1955 Everett 53/3172,884,104 4/1959 Brochard 192/56 R 13 Clams, 5 Drawmg Flgures ;-32 I ep. 34

l 33 l ,25 27" 1 j 231 a l 2s 21. %30 21 \ra 49 23 a 320 d 18; 1 1a 118;23 '17 1e" -15 16 APPARATUS FOR THREADING CLOSURES ONTO BOTTLES ANDSIMILAR CONTAINERS BACKGROUND OF THE INVENTION The present inventionrelates to an apparatus for threading closures onto bottles and similarcontainers.

The use of screw top bottles, that is bottles provided with screw-onclosures are becoming more and more popular. According to one approachin the industry, the so-called pilfer-proof closure is used, a sleevehaving one closed end and consisting of metal. This sleeve is placedover the neck and the open end of the bottle and is then pressed intosealing engagement with the neck under simultaneous deformation of itsmaterial, by appropriate rollers. This type of closure has thedisadvantage that a relatively large number of bottles will be brokenunder the pressure of the rollers.

Another type of closure which is often preferred because it does notinvolve breakage of the bottle when it is applied to the same, is apre-fabricated screw-on closure, frequently of synthetic plasticmaterial, which must be threaded onto the bottle or similar containerafter the latter has been filled.

Evidently, the number of bottles which must be so closed per unit oftime in a modern bottling installation, precludes any thought ofapplying the screw closures manually. For this reason, equipment hasbeen developed which threads the closures onto the bottle or similarcontainer. This equipment is intended to uniformly tighten the screwclosures, but experience has shown that in many instances it does not doso, due to inherent structural difficulties. The result is that someclosures may be excessively tightened and others may not be sufficientlytightened due to the inability of the equipment to apply uniform torqueto the closure.

SUMMARY OF THE INVENTION Accordingly, it is a general object of theinvention to overcome the disadvantages of the prior art.

More particularly, it is an object of the invention to provide animproved apparatus for threading closures onto bottles and similarcontainers, which is not possessed of the aforementioned disadvantages.

Still more particularly, it is an object of the invention to providesuch an improved apparatus which affords a more precise transmission oftorque from the driving component of the apparatus to the threadedclosure.

An additional object of the invention is to provide such an improvedapparatus which permits the torque limit, that is the limit which mustnot be exceeded to assure that the closure is threaded onto thecontainer tightly but not too tightly, will be precisely maintained.

In keeping with the above objects, and with others which will becomeapparent hereafter, one feature of the invention resides in an apparatusfor threading closures onto bottles and similar containers, in acombination which comprises a rotary shaft and rotary closureengagingmeans for entrainingly engaging a closure to be threaded onto acontainer. Coupling means is provided for coupling the engaging meanswith the shaft. It comprises a first coupling member connected for jointrotation with the shaft, and a second coupling member connected forjoint rotation with the engaging means. A plurality oftorque-transmitting elements are provided on one of the members and soyieldably engage a circumferential surface of the other of the membersthat in the event torque exceeds a predetermined limit, a small fractionof the plurality of torquetransmitting elements willy'ieldinglydisengage from the circumferential surface.

Thetorque-transmitting members could be in form of roller bodies, whichare currently preferred, or in form of sliding bodies. For the sake ofconvenience, reference will hereafter be made to roller bodies althoughit should be understood that this term includes sliding bodies also.

With this construction as outlined above, slippage of the coupling uponexceeding of the predetermined torque limit prevents the torque fromdropping to zero, but instead reduces the torque only by a relativelysmall fraction which essentially has the same relationship to theoverall torque as the small fraction of disengaged roller bodies to thetotal number of the plurality of roller bodies. Evidently, the number ofroller bodies involved should be as large as possible, and the number ofroller bodies which at any one time yieldingly disengage should be assmall as possible. It is advantageous if only a single roller body at atime will become disengaged.

The torque-transmitting surface portions which are engaged by the rollerbodies can be in form of a flat sawtooth-shaped profile the distributionof which circumferentially of the axis of rotation will be differentfrom the distribution of the roller bodies. The torquetransmittingsurface can be recessed or can be projecting, the only importantconsideration here being that if the roller bodies are arranged withuniform distribution, the distribution of the sawtooth-shaped profilemust be uneven, or vice versa.

It is currently preferred if the torque-transmitting surface portions ofthat member of the coupling which is not provided with the rollerbodies, are configurated as a gently inclined ramp or groove, which atits highest point forms an abrupt drop back to the level of its lowestpoint. The drop can be so abrupt that even if the roller bodies areclosely adjacent, only one of them can at any time be located at thehighest point where it does not transmit any torque. All other rollerbodies are located on the gently inclined surface of the ramp or grooveand thus transmit torque. If a relatively strong torque is to betransmitted, then the spring force which urges the roller bodies intocontact with the torquetransmitting surface portion, must beappropriately great. The torque transmission behavior can also beregulated by appropriate selection of the spring constants. It isadvantageous if each roller body is provided with a separate springwhich acts only upon it alone.

One of the members of the coupling can be in form of a flat cylindricaldisc which is formed at its circumference with the ramp or groove orsawtooth-shaped profile. In this case the other coupling member mustsurround the first-mentioned one and is preferably provided with radialbores in which roller bodies are located which are urged inwardlyagainst the firstmentioned coupling member by appropriate springs.

However, we currently prefer a construction in which the roller bodiesare mounted in their associated coupling member shiftable in axialdirection, and the ramp or groove is inclined also in axial direction,as will be discussed subsequently.

The roller bodies are either spherical members, which are currentlypreferred, or they are cylindrical rollers or conical rollers.

It is advantageous if the spring force acting upon the respective rollerbodies can be varied, to thereby be able to increase or decrease thetorque limit at which the coupling will experience a torque drop. Thesupports against which the springs bear may be adjustable to permit suchvariation.

It is advantageous if the ramp or groove has a gentle but uniforminclination. This reduces non-uniformity of the transmitted torque whenthe coupling slips, and also facilitates the manufacture of thecomponents.

The ramp or groove advantageously extends over almost the entirecircumference of the coupling, so that only a very short region existsin which preferably only a single roller body at a time will be in aposition in which itwill not transmit torque.

I The roller bodies are advantageously evenly distributed over thecircumference of that coupling member on which they are provided.

The supports for the springs may be pins which are shiftable and havefree ends that are engaged by a member that can be threadedly adjusted,to thereby displace the pins inwardly or outwardly and compress or relaxthe springs.

The coupling according to the present invention can be provided in thespindle which carries the rotary closure-engaging device. However, it iscurrently preferred that it either be located in the closure-engagingdevice itself, or directly between the same and the spindle. The closerthe coupling is located to the closure device, the smaller the inertialforces of the component or components which must be rotated by thecoupling and which act upon the latter.

The novel features which are considered as characteristic for theinvention are set forth in particular in the appended claims. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof, willbe best understood from the following description of specificembodiments when read in connection with the accompanying drawing.

I BRIEF DESCRIPTION OF THE DRAWING DESCRIPTION OF THE PREFERREDEMBODIMENTS Referring now to the drawing it will be seen that we haveillustrated a rotary closure-engaging device provided with a receiver 1which receives a screw-type closure, for instance of synthetic plasticmaterial or the like, that has not been shown but will be understood tobe accommodated in the recess 3 the lower end of which conicallydiverges at 4. This means that the receiver 1 can be readily placed ontothe cap or closure that is'already located on the neck of a bottle whichis to be closed. Also, centering is facilitated with this arrangement.The inner diameter of the recess 3 is slightly larger than the maximumouter diameter of the closure.

Located in the recess 3 is an abutment member 5 mounted on a bolt 6which is axially shiftably mounted in a central bore 7 of thereceiver 1. A threaded pin 8 is provided in a transverse bore of thereceiver 1 and extends into an upwardly and downwardly closed axial slot9 of the bolt 6, thus preventing a turning or fallingdown of the sameand of the member 5. The outer diameter of the member 5 is slightlysmaller than the inner diameter of the recess 3. A spring 10 permanentlyurges the member 5 to its lowest position which is illustrated in FIG.1, so that the member 5 urges the closure (not shown) against the neckof the bottle in overlying relationship with the opening of the bottle.The downward movement of the member 5 is delimited by engagement of theupper end of the slot 9 with the pin 8, and the upward movement islimited by engagement with the pin of the other end of the slot 9. It ispreferable if the member 5 is a hardened steel disc which is removablyconnected to the bolt 6.

The circumferential wall of the receiver 1 is provided with three radialslots in which three engaging members 12 are located, which arepreferably of hardened steel also. As shown in FIG. 1, these members 12each extend inwardly into the recess 3 by approximately 1 mm so thatthey can engage the closure. Each of the members l2 fills the associatedradial slot almost completely. Adjacent the upper ends, the members 12are provided on their radially outer edges with a kerf which is alignedwith an annular groove formed in the outer surface of the receiver 1 andin which a spring ring 13 is located. Since the spring ring also extendsthrough the kerfs of the members 12, it defines for the same a pivotaxis. The radially inner upper end of the members 12 is mounted on aradius the center of which coincides at least substantially with thecenter of the spring ring 13 and which is equal to the width of themembers 12, so that the latter can pivot about the center of the springring 13 but cannot fall out of their slots in normal use. The members 12extend upwardly beyond the spring ring 13 by a distance which is smallerthan their width, so that they can be pivoted far enough in outwarddirection to be removed or to be reinstalled, which facilitates theirremoval for inspection and for replacement. Also, it makes it possibleto insert differently configurated members which can then act uponclosures with differently formed shoulders.

Adjacent the lower ends of the members 12 the receiver l is formed withthe two further annular grooves which are also so located as to coincidewith respective kerfs formed in the members 12. Each of these groovesaccommodates an elastic ring 14 of rubber or synthetic plastic material,or else a fine helical spring. The purpose of the rings 14 is tomaintain the members 12 in the position shown in FIG. 1.

A coupling is provided which limits the torque transmitted by thereceiver 1 upon the non-illustrated closure, in that when a maximumpredetermined torque limit is exceeded, it begins to slip but, inaccordance with the present invention, continues to transmit torque at alevel which is only slightly decreased.

As FIG. 1 shows the coupling is provided with a coupling ring 16 whichis mounted by means of a screw 15 on a portion of the receiver 1 and inthis embodiment constitutes the driven coupling member. The upper sideof the coupling ring 16 is formed with a uniformly inclined groove 16',that is a groove the bottom wall of which is uniformly inclined upwardlyin the direction of rotation which is indicated by the arrow in FIG. 2.Torque-transmitting members in form of spherical elements 17 engage inthis groove 16' which extends along an essentially helical line 17. i

FIGS. 4 and 5 show that the torque-transmitting surface portion 16a ofthe member 16a in another embodiment may also be configurated as agently inclined ramp which at its highest point forms an abrupt dropback to the level of its lowest point.

The torque transmitting members 17, which are roller bodies in theillustrated embodiment, are carried by a further coupling member 21which is the driving coupling member in this embodiment. Each of themembers 17 is accommodated in one of a plurality of axial bores of themember 21. The bores 20 are uniformly and concentrically distributedover the circumference of the member 21 and the members 17 are eachaxially shiftable in the associated bore 20. Springs 19 are provided inthe bores 20 and permanently urge the members 17 via pressure members 18against the bottom of the groove 16', so that by appropriate turning ofthe member 21 the members 17 will transmit torque to the member 16 andcause the same torotate, thus rotating the receiver 1.

The drawing also shows in FIG. 3 that the members 17 and 18 couldbe'replaced by axially shiftable pins 17a located in the respectivebores 20, having free end faces which are accommodated to thecross-sectional configuration of the groove 16' and are slidablyreceived in the latter. However, roller bodies are currently preferred.

If, during the operation of this apparatus, the torque becomes toogreat, that is if it exceeds a predetermined torque limit, then themembers 17 begin to travel in the groove 16', but continue to transmittorque. Only in the region 39 will the transmission of torque beinterrupted, and then only for the single member 17 (or, if the region39 is long enough, the small number of members 17) which can at any onetime be located in the region 39.

The member 21 is indirectly but fixedly connected with a rotary spindleor shaft which is driven in appropriate manner but not illustrated sinceit is conventional. The receiver 1 is tumably journalled on the member21 by means of two ball bearings 23. A screw 24 and a ring 25 prevent itfrom falling downwardly out of the member 21 which latter isconcentrically mounted on a member 26 by means of screws 27.

To make it possible to adjust the force exerted by the springs 19, pins30 are axially shiftably accommodated in the bores 20 above the springs19. These pins 30 form the abutments for the springs 19 and their outerends contact a member 31 which can be turned and thereby be shifted inaxial direction. The member 31 is provided with an upwardly extendingthreaded portion 32 which is threaded with its external thread into aninternal tap bore 33 of the member 26. When it is axially shifted byrotating, the axial position of the pins 30 is changed and thereby thesprings 19 may be compressed or relaxed as required. The member 31 andthe portion 32 are advantageously of one piece with one another.

The portion 32 serves also to connect the entire receiver and couplingwith the previously mentioned spindle. It is provided with a counternutBid to hold it against the member 26. A non-illustrated connectingmember can-be threaded upon the upper portion of the outer thread of theportion 32, to connect the same with the'spindle.

FIG. 2 shows the member 16 in top plan view, to indicate theconfiguration of the groove 16'. It will be seen that from a startingpoint 36 the bottom wall of the groove 16' rises uniformly to a terminalpoint 37, forming a helical line. The arcuate angle included between thepoints 36 and 37 is approximately 350 in the embodiment shown in FIG. 2.Intermediate the point 37 and the point 36, as seen in direction ofrotation, a substantially horizontal portion 3 8 is provided in the cam17' which guides the member 1 7, from which portion 38 the cam 17 dropsabruptly at 39 to return to the starting point 36. Given the dimensionsshown in FIG. 2, twelve of the members 17 may for instance be providedalong the cam 17, being uniformly distributed over the circumference ofthe member 16.

In operation of the apparatus according to the present invention, thelatter descends while being rotated-from above onto the closure which isalready located on a bottle. Different bottle heights can beaccommodated by yielding of the member 5 against the effect of thespring 10. When the receiver first engages the closure, the members 12are initially pressed radially outwardly against the effect of themembers 14, until they can snap into axial grooves which are formed inthe circumference of the closure in accordance with a practice known perse. As soon as this has taken place, the members 12 entrain the closureand thread it onto the neck of the bottle, As soon as the closure istightly threaded onto the neck, the torque acting upon the couplingincreases until the torque limit has been reached, whereupon thecoupling slips and the rotation of the receiver is terminated. After acertain predetermined time, within which the threading-on of a closurewill under all circumstances have been completed, and which can bereadily and empirically determined, the receiver 1 is retracted inupward direction, or else the now closed bottle is removed in downwarddirection. The term bottle used herein for the sake of convenience, isintended to include all such containers which can be provided with ascrew top, e.g. jars, flasks and the like.

It will be understood that each of the elements described above, or twoor more together, may also find a useful application in other types ofconstructions differing from the types described above.

While the invention has been illustrated and described as embodied in anapparatus for threading closures onto bottles and similar containers, itis not intended to be limited to the details shown, since variousmodifications and structural] changes may be made without departing inany way from the spirit of the pres ent invention.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can, by applying current knowledge,readily adapt it for various applications without omitting featuresthat, from the standpoint of prior art, fairly constitute essentialcharacteristics of the generic or specific aspects of this inventionand, therefore, such adaptations should and are intended to becomprehended within the meaning and range of equivalence of thefollowing claims.

What is claimed as new and desired to be protected by Letters Patent isset forth in the appended claims.

1. In an apparatus for threading closures onto bottles and similarcontainers, a combination comprising a rotary shaft; rotaryclosure-engaging means for entrainingly engaging a closure to bethreaded onto a container; and coupling means for coupling said engagingmeans with said shaft, comprising a first coupling member connected forjoint rotation with said shaft, a second coupling member connected forjoint rotation with said engaging means, a plurality of torquetransmitting elements arranged on one of said members around the axis ofrotation of said rotary shaft, and a ring surface on the other of saidmembers, said torque transmitting elements yieldably engaging said ringsurface and said ring surface surrounding said axis of rotation, saidtorque transmitting elements being movable in directions the inclinationof which relative to said axis of ro tation is common for all torquetransmitting elements and said ring surface gradually rising slightlyfrom a first level to a second level and descending steeply at only onepart of its circumference from said second level to said first level,the direction of rising and descending of said ring surface being thedirection in which said torque transmitting elements are movable.

2. A combination as defined in claim 1, wherein said surface of saidsecond member is provided with a sawtooth-shaped profile having profileportions which are arranged at a different spacing than saidtorquetransmitting elements.

3. A combination as defined in claim 1, wherein said torque-transmittingelements are roller bodies.

4. A combination as defined in claim 1, wherein said torque-transmittingelements are glide bodies.

5. A combination as defined in claim 1, wherein said surface has aportion which forms a ramp.

6. A combination as defined in claim 1, wherein said surface has aportion which forms a groove.

7. A combination as defined in claim 5, wherein said ramp extendsaxially of the axis of rotation of said coupling means, saidtorque-transmitting elements being shiftable axially of said axis ofrotation.

8. A combination as defined in claim 1; further comprising springbiasing means acting upon said torquetransmitting elements and biasingthem towards said surface, said biasing means being adjustable forvarying said predetermined limit.

.9. A combination as defined in claim 1, wherein said rise is of uniformpitch.

10. A combination as defined in claim 1, wherein saidtorque-transmitting elements are uniformly distributed about saidsurface.

1 1. A combination as defined in claim 8, wherein said biasing meanscomprises biasing springs, and adjustable supports on which said biasingsprings bear and which are adjustable toward and away from said surface.

12. A combination as defined in claim 11, wherein said supports areshiftable pins each having a free end; and further comprising adjustingmeans engaging said free ends and operative for shifting said pins.

13. In a slip clutch, a combination comprising a rotary shaft; rotarymeans; and coupling means for coupling said rotary means with saidshaft, comprising a first coupling member connected for joint rotationwith said shaft, a second coupling member connected for joint rotationwith said rotary means, a plurality of torque transmitting elementsarranged on one of said members around the axis of rotation of saidrotary shaft, and a ring surface on the other of said members, saidtorque transmitting elements yieldably engaging said ring surface andsaid ring surface surrounding said axis of rotation, said torquetransmitting elements being movable in directions the inclination ofwhich relative to said axis of rotation is common for all torquetransmitting elements and said ring surface gradually rising slightlyfrom a first level to a second level and descending steeply at only onepart of its circumference from said second level to said first level,the direction of rising and descending of said ring surface being thedirection in which said torque transmitting elements are movable.

1. In an apparatus for threading closures onto bottles and similarcontainers, a combination comprising a rotary shaft; rotaryclosure-engaging means for entrainingly engaging a closure to bethreaded onto a container; and coupling means for coupling said engagingmeans with said shaft, comprising a first coupling member connected forjoint rotation with said shaft, a second coupling member connected forjoint rotation with said engaging means, a plurality of torquetransmitting elements arranged on one of said members around the axis ofrotation of said rotary shaft, and a ring surface on the other of saidmembers, said torque transmitting elements yieldably engaging said ringsurface and said ring surface surrounding said axis of rotation, saidtorque transmitting elements being movable in directions the inclinationof which relative to said axis of rotation is common for all torquetransmitting elements and said ring surface gradually rising slightlyfrom a first level to a second level and descending steeply at only onepart of its circumference from said second level to said first level,the direction of rising and descending of said ring surface being thedirection in which said torque transmitting elements are movable.
 2. Acombination as defined in claim 1, wherein said surface of said secondmember is provided with a sawtooth-shaped profile having profileportions which are arranged at a different spacing than saidtorque-transmitting elements.
 3. A combination as defined in claim 1,wherein said torque-transmitting elements are roller bodies.
 4. Acombination as defined in claim 1, wherein said torque-transmittingelements are glide bodies.
 5. A combination as defined in claim 1,wherein said surface has a portion which forms a ramp.
 6. A combinationas defined in claim 1, wherein said surface has a portion which forms agroove.
 7. A combination as defined in claim 5, wherein said rampextends axially of the axis of rotation of said coupling means, saidtorque-transmitting elements being shiftable axially of said axis ofrotation.
 8. A combination as defined in claiM 1; further comprisingspring biasing means acting upon said torque-transmitting elements andbiasing them towards said surface, said biasing means being adjustablefor varying said predetermined limit.
 9. A combination as defined inclaim 1, wherein said rise is of uniform pitch.
 10. A combination asdefined in claim 1, wherein said torque-transmitting elements areuniformly distributed about said surface.
 11. A combination as definedin claim 8, wherein said biasing means comprises biasing springs, andadjustable supports on which said biasing springs bear and which areadjustable toward and away from said surface.
 12. A combination asdefined in claim 11, wherein said supports are shiftable pins eachhaving a free end; and further comprising adjusting means engaging saidfree ends and operative for shifting said pins.
 13. In a slip clutch, acombination comprising a rotary shaft; rotary means; and coupling meansfor coupling said rotary means with said shaft, comprising a firstcoupling member connected for joint rotation with said shaft, a secondcoupling member connected for joint rotation with said rotary means, aplurality of torque transmitting elements arranged on one of saidmembers around the axis of rotation of said rotary shaft, and a ringsurface on the other of said members, said torque transmitting elementsyieldably engaging said ring surface and said ring surface surroundingsaid axis of rotation, said torque transmitting elements being movablein directions the inclination of which relative to said axis of rotationis common for all torque transmitting elements and said ring surfacegradually rising slightly from a first level to a second level anddescending steeply at only one part of its circumference from saidsecond level to said first level, the direction of rising and descendingof said ring surface being the direction in which said torquetransmitting elements are movable.